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[reaction: see text] The enantioselective aldol reaction using a novel binuclear zinc catalyst of acetone with several aldehydes gave products in good yields (62-89%) with a high level of enantioselectivity (ee = 76-92%).

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The polymers presented in this paper are designed for the intended use in light-emitting diodes. The synthesis of a new series of macromolecules containing isolated oligothiophene, oligothienylene vinylene, or bithiazole conjugated units bridged by aliphatic units is presented along with optical characterization by UV−vis absorption and fluorescence spectra in solution. These polymers gave very similar optical traits to their corresponding subunits while possessing the physical characteristics of a macromolecule.

The synthesis of nine new polymers intended for future use in light‐emitting diodes is described. The polymers consist of alternating units of thiophene–arylidene–thiophene chromophores and saturated silicon‐containing spacers. The arylidene moieties include benzene‐1,4‐, 2,5‐dimethoxybenzene‐1,4‐, naphthalene‐1,4‐, anthracene‐9,10‐, pyridine‐2,5‐, pyridine‐2,6‐, N‐methylcarbazole‐3,6‐, 1,3,4‐oxadiazole‐2,5‐, and 4,4′‐dimethyl‐2,2′‐bithiazole‐5,5′‐. The syntheses involved dibromination of the central arene followed by Suzuki or Kumada cross‐coupling reactions with two thiophene units. Subsequent dilithiation and reaction with dihalosilylalkanes provided the polymers. Their optical properties, including ultraviolet–visible absorption and emission in solution, were comparable to those of the parent monomer units, and they possessed the physical characteristics of macromolecules. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 872–879, 2001